I have aquired, to help out a neighbor, 5 koi which are too big for her pond. They are 12" to 15" I have the room. No problem. I have one pond that is an odd shaped 18ish x 25ish & 3' deep. Bottom drain,4' falls & an areator. Most of my lillies are there. Problem is we have had soooo much rain the water is very murky looking. I can not see the koi. They are swimming at the bottom & I can hardly see them. Will the koi do well in this pond filled with rain water? What should I do to ensure these fish do alright? Thanks in advance for any advice.